Silicon steel coils are stacked into cores after longitudinal shearing. The quality control of cores should generally include punching holes of various shapes, grooves of various shapes, and various sheet shapes of longitudinal shearing silicon steel strips. So what is the close relationship between the longitudinal shear and the quality of iron core?
It is important to know the burr size of iron core to measure the quality of vertical shear of iron chips. Big burr will not only cause short circuit and increase eddy current loss, but also seriously affect the size and quality of overlapping and increase iron loss. Therefore, the punching and shearing workers are required to do everything possible to reduce burrs or take some means to remove the burrs.
In the process of longitudinal shearing with longitudinal shearing machine, burrs are more or less always present. Transformer allows burr height below 0.03mm, otherwise, it must be treated by embossing. In fact, if the die clearance is reasonable, the two cracks starting from the edge of the punch and the die will be connected into a straight line. The minimum size of the blanking workpiece is equal to the punch size, while the maximum size is equal to the punch size, and the quality of the workpiece is good.
Therefore, when installing the cutter in the longitudinal shear machine, the operator must carefully find the correct line to ensure that the center line of the upper die overlaps, is not eccentric, and does not intersect. The clearance around the edge is uniform, which prevents one side from contacting first, and one side from contacting later. In addition to requiring die designers to correctly select die materials, structures and clearances, and manufacturers to strictly handle, grind and other key points, so as to make the molds qualified, but also must put forward strict requirements for the operators.
In addition to burrs, the processing quality of the longitudinal shear machine is also reflected in the straightness of the core. The deviation of the cutting edge is a response of the magnitude of internal stress, which can not be eliminated by the longitudinal shear machine. The elimination of internal stress should start from the material itself. In the process of longitudinal shearing, the deviation of cutting edge determines the straightness of material.
Usually this deviation forms different arcs of convex and concave, half of which radiate, and the maximum allowable radian should not exceed 0.8mm within 1.5m. Because of the errors caused by fluctuation disturbance of power supply, gas source, hydraulic system, oil temperature and so on, only stabilization, decompression and constant pressure devices can be added to these power systems. For electronic systems, various shielding must be added to prevent various disturbances. Under the existing conditions, operators are required to familiarize themselves with the control systems and adjustment methods of the equipment so as to find out the causes in time and deal with them.